- document
- Caires, S. (author), Doorn, N. (author), Groeneweg, J. (author), Dongeren, A.R. van (author) report 2006
- document
- Vledder, G.P. van (author), Hurdle, D.P. (author), Groeneweg, J. (author) report 2002
- document
- Haaren, Y.H.G. van (author), Spaan, G.B.H. (author) report 1997